ac compressor wiring question

[aboesec10]

hey all! have a question regarding my ac compressor. Ive installed a 2015 lt1 from a silverado and am using the stock gm ac compressor. Ive wired the clutch to the binary switch. My question is do i need to wire the compressor solenoid to the same input? Obviously the silverado wiring diagram shows the on/off signal from the ac control module, which I obviously didn't use. Im running the gen iv vintage air kit. The clutch operates correctly like it should yet it doesn't build any pressure in the system

[Andy4639]

The clutch operates correctly like it should yet it doesn't build any pressure in the system

I'm not sure if I following your statement.
If the clutch is engaging and working then it has to be putting pressure into the system.
Well at least the older systems does anyway.

[chevyguyase]

Your clutch seems to work? I think you have other problems. Make sure you have oil in your compressor. Is the system charged? Can you give us the pressure readings on the low and high sides? If it's charged, you may have an expansion valve missing or stuck open. Give us some more info, well be glad to help.

[aboesec10]

Yeah the clutch engages like it should. Looking at the wiring diagram above i think i need to put positive voltage to the solenoid to allow the compressor to compress. We've pulled the pressure back off of the system to fix a small leak in an oring. I will charge it back up next week with power to the solenoid and see if thats the issue. I wanted to use a vintage air compressor but couldn't find one to fit where i needed it and there are no brackets etc. available for these engines yet.

[VetteVet]

Originally Posted by aboesec10

Yeah the clutch engages like it should. Looking at the wiring diagram above i think i need to put positive voltage to the solenoid to allow the compressor to compress. We've pulled the pressure back off of the system to fix a small leak in an oring. I will charge it back up next week with power to the solenoid and see if thats the issue. I wanted to use a vintage air compressor but couldn't find one to fit where i needed it and there are no brackets etc. available for these engines yet.

They have changed the systems so much since the 70's, but as I understand it the clutch was controlled by the binary switch based on the static charge pressure of the coolant. If you have a lower than designed pressure then the switch wouldn't close, and engage the clutch. In order to pressurize the switch, the flow control valve had to be opened.

This was done when the AC controller was selected for AC via the B+ wire in the diagram. The diagram leaves out the power source for the clutch relay and the solenoid valve. Another question, is the solenoid built into the compressor or is it a separate inline valve in your system?




Researching Gen Air's website shows better diagrams but you aren't using their controller or compressor. I wouldn't recommend running the clutch until you figure out how to open the valve first.

[VetteVet]

Here's another wiring diagram that shows it a little better.





I think the low and high pressure switches act as the flow controls.

[gmachinz]

Mechanically speaking, have you pulled a good vacuum each time you've opened the system? You aren't "jumping" the clutch to engage are you?

[aboesec10]

so looking at your diagrams, the solenoid should be constant 12 volts with the binary switch controlling the compressor clutch? As is the clutch engages when plugged into the binary switch. My initial thought was to have the binary switch engage both the solenoid and clutch. Its tied into the vintage air system so obviously thats the only high/low pressure switch in the system.

[VetteVet]

Rather than speculate on what you should do, or not do, based on the mix of the two systems, I would suggest that you take the truck to an AC specialist near you who could look at what you have, and recommend the correct solution.